DIY Electric Car Forums banner

21 - 40 of 42 Posts

·
Registered
Joined
·
20 Posts
Discussion Starter #21
FYI they stopped sales of LG Chem batteries to the public. So unless you can source used ones from Pacifica Hybrid, you might need to reconsider your battery options.
Any recommendations ?
 

·
Registered
Joined
·
6 Posts
I am going to make my own project too. I have Tesla rear-drive unit but I am considering hatchbacks like a donor car. Any advice welcome. Maybe someone has experience with the build.
 

·
Registered
Joined
·
4,907 Posts
The Stealth EV “kits” come with more than just drive unit and control board.

I bought their small rear and front drive unit kits for my 2003 Mitsubishi Evolution 8 conversion. Check the link below for thread where I posted pics of the kit received and listing of items...
They may have sold different combinations of parts - the link from JReyes explicitly says that it is just the drive unit with controller. It would be bad to order a drive unit expecting an extensive kit, and get just the drive unit. On the other hand, the Stealth EV website might just be horribly bad. ;)

If the drive unit kit comes with everything that 4G63T described in the other thread (in which case it is still a drive unit kit, not a complete EV conversion kit), then the major additional components needed would include
  • battery modules, interconnection wiring, brackets, thermal management (cooling) plates, and housing
  • Battery Management System with wiring to modules
  • onboard charger
  • charging inlet and anything needed to manage it
  • HV DC to 12 V DC converter
  • instrumentation
  • radiator and plumbing for drive unit cooling, plus for battery cooling (if battery is liquid-cooled)
  • anything needed to power systems that were run from the engine, such as hydraulic power assist for steering (not likely in a car this new), vacuum assist for braking, and air conditioning
 

·
Registered
Joined
·
4,907 Posts
The LG Chem 16S modules which were widely sold are used in the Chrysler Pacifica Hybrid. You could salvage from them, just as all of the Leaf, Tesla, and Chev Volt battery modules and complete packs are salvaged from those cars... although the Pacifica will be relatively rare and hard to find.


When you are trying to assemble about 30 kWh of modules and you use these 16S modules (or the similarly configured modules from other plug-in hybrids), you end up having to build two strings and put them in parallel. It is simpler to use just one string of higher-capacity modules, like every production EV. Running typical modern EV voltage (which implies about 96S battery configuration), that means one complete set of modules from an EV which has about the desired capacity (a later Nissan Leaf? VW e-Golf? Kia Soul?) or a set of aftermarket modules.
  • 12 LG Chem Pacifica modules (31 kWh) would have a volume of 144 litres and weigh 204 kg
  • 14 LG Chem Pacifica modules (36 kWh) would have a volume of 168 litres and weigh 238 kg
Zero EV lists two different modules which are each about the same size (smaller than the LG Chem Pacifica modules), and are configured with more cells in parallel and fewer in series, to get more Ah capacity per module:
These are probably not made by Zero EV so perhaps they are available from other suppliers as well. Both seem high in capacity for their size; they may be rated less conservatively than the Pacifica modules. The 2017 and later VW e-Golf uses a large number of roughly this size of module with 4S3P configuration, rated lower in capacity (again perhaps because it is just rated conservatively).

Modules of this same size with the same number of the same cells but configured 6S2P would probably suit a lot of DIY projects... but I haven't seen that combination offered.
 

·
Registered
Joined
·
4,907 Posts
Here’s the link to the product :
Why use the expensive "Ludicrous" version of the drive unit? Even the least expensive base large drive unit is capable of more power than the proposed battery can safely provide, and is thousands of dollars less expensive.

The small rear drive unit might be enough, and would be lighter and more compact (although about the same price as a base large drive unit).
 

·
Registered
Joined
·
20 Posts
Discussion Starter #26
Why use the expensive "Ludicrous" version of the drive unit? Even the least expensive base large drive unit is capable of more power than the proposed battery can safely provide, and is thousands of dollars less expensive.

The small rear drive unit might be enough, and would be lighter and more compact (although about the same price as a base large drive unit).
So basically my only option at this moment would be getting a whole Tesla 16 module pack correct ?
 

·
Registered
Joined
·
69 Posts
They may have sold different combinations of parts - the link from JReyes explicitly says that it is just the drive unit with controller. It would be bad to order a drive unit expecting an extensive kit, and get just the drive unit. On the other hand, the Stealth EV website might just be horribly bad. ;)

If the drive unit kit comes with everything that 4G63T described in the other thread (in which case it is still a drive unit kit, not a complete EV conversion kit), then the major additional components needed would include
  • battery modules, interconnection wiring, brackets, thermal management (cooling) plates, and housing
  • Battery Management System with wiring to modules
  • onboard charger
  • charging inlet and anything needed to manage it
  • HV DC to 12 V DC converter
  • instrumentation
  • radiator and plumbing for drive unit cooling, plus for battery cooling (if battery is liquid-cooled)
  • anything needed to power systems that were run from the engine, such as hydraulic power assist for steering (not likely in a car this new), vacuum assist for braking, and air conditioning
yes their kits include all of my listed items. His website needs to be updated lol . I already let Matt know , when we last spoke . Hopefully soon he will get that taken care of . But I highly recommend anyone interested to give him a call to discuss what your needs are.

I decided to buy a “kit” rather than sourcing a drive unit and open source etc.. because I simply wanted a proven kit and not risk a dud drive unit . Also I doubt my skills a little and wanted as close to complete or plug and play as I could pay for at reasonable price .
 

·
Registered
Joined
·
4,907 Posts
So basically my only option at this moment would be getting a whole Tesla 16 module pack correct ?
If you want to use "Ludicrous" power level you need a lot of battery, or a battery of specialty high-power cells. Tesla only allows power that high from the 100 kWh battery, but it may not have to be quite that large and doesn't have to be from Tesla - two 15 kWh packs are well short of that. You do need 360 volts (nominal) to run the full rated power of any of the model variants that come with 16 modules, at least at higher speed.
 

·
Registered
Joined
·
20 Posts
Discussion Starter #29


According to this products specs a ten Tesla pack battery would be 53 kw pack

Would produce about 450hp for about 3 seconds and 350hp for about 10 seconds
About 1.35 hp per kw
 

·
Registered
Joined
·
4,907 Posts
...

According to this products specs a ten Tesla pack battery...

Would produce about 450hp for about 3 seconds and 350hp for about 10 seconds
If those values are correct, they are way short of "Ludicrous"... which is why I wonder why you would pay for that version.
 

·
Registered
Joined
·
20 Posts
Discussion Starter #31
If those values are correct, they are way short of "Ludicrous"... which is why I wonder why you would pay for that version.
I wrote to them because the specs on the three motors they provide are exactly the same maybe is a typo
 

·
Registered
Joined
·
4,907 Posts
I wrote to them because the specs on the three motors they provide are exactly the same maybe is a typo
No, they're not. The text descriptions are the same (because they're for the whole series of Tesla drive units in general, but the maximum values of current, power, and torque are different:

Base
Max Current900 Amps DC
Max Power335 kW (450 Hp)
Max Torque450 Nm (330 lb-ft)

Performance
Max Current1150 Amps DC
Max Power400 kW (536 Hp)
Max Torque600 Nm (445 lb-ft)

Ludicrous
Max Current1400 Amps DC
Max Power475 kW (645 Hp)
Max Torque650 Nm (480 lb-ft)

Other specs are the same because they are limited by mechanical factors, not the controller.
 

·
Registered
Joined
·
482 Posts
The power is in the batteries. You can have all the ludicrous in the world and it won't put the power out unless it can pull it fast enough from the pack. The Tesla Ps use every electron from their giant battery packs at full throttle. The standard Model S has something like 16 55lb modules.

For batteries you're looking at Model S modules or the new OX Drive batteries from Electric GT (that don't quite exist in the wild yet). If you want to keep your rear seats, you're looking at a lot lot of fabrication to get them in that tunnel...They are not small. The more you have, the more power you can pull for longer.

How good are your fabrication skills and what are your actual goals? That's where most of the time is spent (for me, anyway). If I were you, I'd adapt a Nissan Leaf motor to the existing transmission and put some batteries behind the front seat, aiming for 53% of the weight in the rear. This is the cheapest way to an EV conversion, and that'll run you $10-15k in parts if you use the batteries. It will be a slower car with much less range, but your 0-60 time will still be limited by traction (or the strength of the drivetrain). Even the lowly Leaf puts out wicked torque to the wheels through a manual transmission.

I love the 86, and it seems like it would be superb with just a bit more torque, but keep in mind that—any way you slice it—it would be cheaper to just buy a Tesla.
 

·
Registered
Joined
·
4,907 Posts
The power is in the batteries. You can have all the ludicrous in the world and it won't put the power out unless it can pull it fast enough from the pack. The Tesla Ps use every electron from their giant battery packs at full throttle. The standard Model S has something like 16 55lb modules.
True. Early Tesla Model S variants (up to 60 kWh?) have 14 modules; higher capacity variants have 16 modules. The modules themselves vary (the higher-capacity variants have more cells per module). The highest motor power is only allowed with the largest battery variants, and the higher voltage of the 16-module battery will be needed for the motor to produce the higher power levels.
 

·
Registered
Joined
·
20 Posts
Discussion Starter #35
The power is in the batteries. You can have all the ludicrous in the world and it won't put the power out unless it can pull it fast enough from the pack. The Tesla Ps use every electron from their giant battery packs at full throttle. The standard Model S has something like 16 55lb modules.

For batteries you're looking at Model S modules or the new OX Drive batteries from Electric GT (that don't quite exist in the wild yet). If you want to keep your rear seats, you're looking at a lot lot of fabrication to get them in that tunnel...They are not small. The more you have, the more power you can pull for longer.

How good are your fabrication skills and what are your actual goals? That's where most of the time is spent (for me, anyway). If I were you, I'd adapt a Nissan Leaf motor to the existing transmission and put some batteries behind the front seat, aiming for 53% of the weight in the rear. This is the cheapest way to an EV conversion, and that'll run you $10-15k in parts if you use the batteries. It will be a slower car with much less range, but your 0-60 time will still be limited by traction (or the strength of the drivetrain). Even the lowly Leaf puts out wicked torque to the wheels through a manual transmission.

I love the 86, and it seems like it would be superb with just a bit more torque, but keep in mind that—any way you slice it—it would be cheaper to just buy a Tesla.
In this case I would be using the performance model motor with 10 cells of the 85 kw pack, about fab a roll cage including reinforcements for battery pack at the engine bay and rear to a install of he motor, the leaf is not sold here so sourcing it here it is not an option and laso no because race car lol, Tesla’s run around 80k here so that not an option also not the intended purpose of the build.
 

·
Registered
Joined
·
20 Posts
Discussion Starter #36
True. Early Tesla Model S variants (up to 60 kWh?) have 14 modules; higher capacity variants have 16 modules. The modules themselves vary (the higher-capacity variants have more cells per module). The highest motor power is only allowed with the largest battery variants, and the higher voltage of the 16-module battery will be needed for the motor to produce the higher power levels.
That’s why I’m moving with performance motor model
 

·
Registered
Joined
·
317 Posts
"Ludicrous" has a lot more to do with the battery, than the drive unit, afaik. I think that's just a performance LDU.

I doubt you'll be able to dump ludicrous amounts of current into the inverter of a PLDU with the pack you propose to use.
 
21 - 40 of 42 Posts
Top